What does Stallman or his views have to do with it? The GPL is a document that is interpreted by judges and juries, not by Stallman.
The text of the GPL itself makes no distinction between software or other things that can be copyrighted. GPLv3 even changes its language to make it clearer that it can be applied to non-software things. For example, it defines "source code" as "the preferred form of the work for making modifications to it". What this actually means is up to the aforementioned judges and juries, but for a movie, it's conceivable that the preferred source for modification is indeed the 3d models, the original reels, and so forth.
However, I am not sure how a judge or a lawyer would interpret the word practical work.
This is nothing that would ever be covered or considered to be covered by the license. It's a screen shot of source code.
I don't think - well I know he's not - entitled to acknowledgement either, any more than the producers of a movie would be required to acknowledge the NYT because one of the characters is reading it in a coffee store.
http://www.gnu.org/philosophy/funding-art-vs-funding-softwar...
Note: I only have a superficial understanding of GPL and Stallman's views.